1. Field of the Invention
The present invention relates generally to assessing neural excitation, and more particularly, to assessing neural excitation associated with an implanted electrode array.
2. Related Art
Prosthetic implants systems are now being used to directly deliver electrical stimulation to auditory nerve fibers of a recipient's cochlea to cause the recipient's brain to perceive a hearing sensation resembling the natural hearing sensitivity normally delivered to the auditory nerve. One form of such a prosthetic hearing implant system is a Cochlear implant. An example of a cochlear implant system is described in US Patent Publication 2006/0247735 (the contents of which are here and incorporated by this reference).
The relationship between the hearing sensation afforded to the recipient of the cochlear implant and the excitation of the electrodes in the electrode array varies from recipient to recipient. Consequently it is important to be able to determine the neural excitation profile of the electrode array. In particular the locus of excitation for each electrode in the cochlea array is typically unknown. Some electrodes may stimulate locally, others more broadly. In some cases the stimulus may jump across turns and excite at two places.